DPD is abbreviated form of
DPD is abbreviated form of diffusion pressure deficit.The term was given by Meyer.
Good soil is
Good soil allows percolating of the water slowly from it.
Deplasmolysis is a process of ____.
Deplasmolysis is a process of recovery of a plasmolysed plant cell. When a plasmolysed cell is placed inside a hypotonic solution, water from the solution moves into the plasmolysed cell, causing it to regain it original cell volume.
Stomata of a plant open due to
During day time, due to photosynthesis, malic acid forms which breaks to H+ and malate. H+ move out of guard cells and K+ enter forming potassium malate which makes guard cells turgid and stomata opens.
Guttation is mainly due to
Loss of water from margins of leaves is called guttation. Guttation occurs when transpiration rate is very low as compared to rate of water absorption. Due to which root pressure is developed and water is pushed out through stomata like pores called hydathodes. It occurs in more saturated atmosphere.
At what time the stomatal transpiration in plants is almost completely stopped ?
Stomata of most of the plants close during night and hence stomatal transpiration is stopped at night.
What happens when osmosis occurs with unloading of sugar at the sink?
At sink, unloading of sugar occurs. Therefore, due to solute gradient osmosis occurs and water flows out of the phloem.
Stomata open and close due to
Turgor pressure is the pressure that develops in a cell due to osmotic diffusion of water inside it and is responsible for pushing the membrance against cell wall. Stomata open under conditions of increased turgor pressure of guard cell and stomata get closed under conditions of decreased turgor pressure of guard cells. When turgid, they swell and bend outward. As a result, the stomatal aperture opens. When they are flacid, the tension from the wall is relased and stomatal aperture closes.
Which among the following plant organs have more aquaporins in their cell membrane?
Option B is the correct answer. Roots are the organs that are involved in the intake of water from the soil. So it must have a high capacity to take water. Apart from osmosis and diffusion, the root hair cells facilitate diffusion of water through the aquaporins that span their cell membrane.
Which among the following parts in roots absorb water and mineral ions?
Root hairs are extensions of the epidermal cells. They have thin cell walls so that water and mineral ions can easily be absorbed from the soil. So option B is the correct answer.
Water in plants is transported by ascent of sap takes place through
Water in plants is transported by ascent of sap takes place through xylem.
The principal pathway of water translocation in angiosperms is
Water movement occurs through the tracheary elements of xylem.
The unit of water potential is ____.
Water potential is measured in mega pascal (MPa).
Which among the following is created by osmotic pressure of the xylem sap?
Root pressure is created by osmotic pressure of the xylem sap. So option C is the correct answer.
Bidirectional translocation of minerals takes place in
Minerals can move upward and downward (bidirectional movement) as well as laterally in phloem. Phloem plays an important role in translocation of organic food and minerals.
Where does "phloem-loading" occur?
Option B is the correct answer. Phloem loading is the process where sugars are loaded in phloem by "source cells". Among the given options, leaves (option B) are the source, where sucrose is produced. Sucrose from leaves is loaded into the phloem elements for sugar transport.
If a cell swells, after being placed in solution, the solution is
If a cell swells, after being placed in solution, the solution is called Hypotonic.
The translocation of organic solutes in sieve tube is supported by
P-proteins is the supporting factor for the translocation of organic solutes in sieve tubes.
Which among the following is not needed for mineral absorption in plants?
Phloem is not required for mineral absorption. Some mineral ions from soil cannot easily pass through the cell membrane of root cells. So energy is required by root cells for absorbing mineral ions from soil. Ions are dissolved in water, so water is required to transport mineral ions. Xylem is required to transport water and minerals in plants. So option D is the correct answer.
The water potential and osmotic potential of pure water are
Osmotic potential is the potential of a solution to cause water movement into it across a semipermeable membrane. Water potential is the tendency of water to leave a system.
Active and passive transports across cell membrane differ in
Active transport always involves the expenditure of energy for the movements of substances against concentration gradient.
Transpiration differs from evaporation in
Transpiration differs from evaporation because it is a physiological process while evaporation is a physical process.
____ cells act as sink of sugar.
Fruit cells act as sink. Mesophyll cells produce sugars. Sink cells are the cells that do not make enough sugars for their growth. They rely upon leaves for sugars. Sugars from the leaves are translocated to fruits, which need high sugar content. That is why fruits are sweet.
Root hairs are the extensions of root ____ cells.
Epidermis is the outermost layer of the roots. The cells of the epidermis protrude outward to form the root hairs.
The rate of flow of sap through a xylem pipe depends upon the ____.
The rate of flow of sap through a xylem pipe depends upon the diameter of the pipe. More the diameter, more the rate of flow of xylem sap. Less the diameter of xylem tube, lesser the rate of flow of xylem sap. Note: Xylem tubes are non-living. So they do not have any cell organelles or nucleus.
Excessive supply of chemical fertilizers often causes death of crop plants due to
Excessive supply of chemical fertilizers often causes death of crop plants due to exosmosis.
Which of the following plant is found to have minimum transpiration ?
Cactus is a xerophytic plant and have sunken stomata to reduce the rate of transpiration, confined to lower epidermis.
Humus in soil is necessary for plant growth because it
Humus in soil is necessary for plant growth because it increases aeration and water absorption capacity of soil.
Why plasmolysed cell appears flaccid. The cell would have ____.
A plasmolysed cell would have lost water and become flaccid. If a plant cell is placed in a hypertonic medium, the cell loses water and becomes flaccid or shrunken. Further, it can cause plasmolysis due to further loss of water.
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